RADIOACTIVE 35-SULFUR (pdf), Antra Priyadarshi and Mark H Thiemens, June 2012: [...] we were the first to recognize the nuclear core meltdown at Fukushima and estimate the neutron leakage from the core element rubble. Our ongoing measurement in samples collected from Japan shows that Fukushima was active even after 7 months of the disaster . . . → Read More: Experts: Nuclear chain reactions may have lasted over 7 months at Fukushima — Neutron leakage from ‘active’ molten fuel — “Core producing radioactive sulfur” — Top Gov’t Official: MOX fuel could be neutron source
A confession of an ex-Tepco worker Translated by: Goldieluvmj Original Upload: LunaticEclipseKimura First broadcast: Nov 25 2011 Published: Apr 11, 2012 Via TBS Blog: Confession of TEPCO employees, 2011/11/29 17:56 h/t arclight
Subtitles have been embedded on this clip for those having trouble viewing via CC button in YouTube toolbar — Watch the full . . . → Read More: Ex-Fukushima Daiichi engineer as ‘cold shutdown’ declared: Fuel rods still active and alive — Most worried about recriticality — Tepco must measure neutrons near core (VIDEO)
Follow-up to: Just-Published Study: Plutonium being found away from Fukushima is from nuclear fuel fragments blown out after explosions
Title: Plutonium near Fukushima plant poses little risk, study says Source: Los Angeles Times Author: Amina Khan (Ralph Vartabedian contributed to report) Date: March 8, 2012 Emphasis Added
[...] In the area around the Fukushima . . . → Read More: L.A. Times: Speculation that “supercritical fission event” occurred at Fukushima reactor irradiating plutonium, says nuclear expert — Explosion so massive investigators found fuel rod fragments a mile away
Title: TEPCO: No.2 reactor thermometer likely broken Source: NHK Date: Tuesday, February 14, 2012 15:32 +0900 (JST)
[...] The operator denied the possibility of the reactor heading toward criticality again, as it has not detected any radioactive xenon, which would be generated from continuous nuclear fission.
It says it will continue to circulate water . . . → Read More: NHK: Tepco told to find ways of measuring temperature at Reactor No. 2 and report by tomorrow — Still claimed no xenon detected
>> UPDATE: *Now 90+°C?* Update as of 2:45 am ET on Feb. 12: Asahi Reporter: Tepco graph shows spike above 90°C at Reactor No. 2 — Exactly how high have temperatures gone?
Title: JUST IN: #Fukushima Reactor 2 RPV Bottom Temperature at 82 Degrees Celsius Source: EX-SKF Date: Feb 11, 2012
Fukushima Reactor 2 . . . → Read More: 82°C at Reactor No. 2 — Keeps rising even after injection of more water — Tepco “set to dump in boric acid”
Title: Stabilisation after Fukushima cooling changeSource: World Nuclear NewsDate: Feb 7, 2012 [...] Tepco was able to discount recriticality as a potential cause of the temperature rise after conducting an analysis of charcoal filters in the containment gas control system. These showed very low traces of fission products that were below the threshold that . . . → Read More: Nuclear Industry Website: Recriticality test detects “very low traces” of fission products at Reactor No. 2 — Tepco then injected boric acid as a precaution against chain reactions
Title: TEPCO struggles to cool Fukushima plant’s No. 2 reactor Source: AJW by The Asahi Shimbun Author: Takashi Sugimoto and Jin Nishikawa. Date: February 07, 2012
Tokyo Electric Power Co. is taking steps to prevent a possible self-sustaining nuclear chain reaction at the crippled Fukushima No. 1 nuclear power plant. [...]
“We expect them . . . → Read More: Exposed? Asahi: Water may not be reaching part of melted nuclear fuel from Reactor No. 2, says unnamed Tepco official
Title: Reactor No. 2 heats up, gets more waterSource: KyodoDate: Feb. 7, 2012 [...] the amount of water injected into reactor 2 on Tuesday [is] the highest level since the plant achieved cold shutdown in December as concerns grew over rising temperatures [...]
[...] Tepco needed more time to assess the effectiveness of the . . . → Read More: Tepco: Recriticality “probably” did not occur at Reactor No. 2 — “Difficult to judge” whether temperature rising or falling
Title: Tepco Tackles Nuclear Reaction Threat as Fukushima Plant Temperature Rises Source: Bloomberg By: Tsuyoshi Inajima Date: Feb 6, 2012
Tepco Tackles Nuclear Reaction Threat as Fukushima Plant Temperature Rises
Tokyo Electric Power Co. injected boric acid into a reactor at its crippled Fukushima nuclear plant to prevent an accidental chain reaction known as . . . → Read More: Bloomberg: “Nuclear reaction threat” as temperature rises — Head of Japan nuke institute: “Nobody is sure about the location of melted fuel — A similar incident will probably occur again”
Title: Tepco Injects Boric Acid Into Fukushima No. 2 Reactor Source: Bloomberg Author: Takehiko Kumakura Date: Feb 6, 2012 6:20 PM ET
Tokyo Electric Power Co. said the temperature of the No. 2 reactor at its damaged Fukushima nuclear plant has risen and it injected boric acid into the unit early this morning to . . . → Read More: Bloomberg: Tepco injects boric acid to prevent criticality at Reactor No. 2
Title: Temperature at No.2 reactor remains high Source: NHK Date: Monday, February 06, 2012 20:48 +0900 (JST)
Attempts to cool the temperature in the No. 2 reactor of the disabled Fukushima Daiichi nuclear power plant have only partially succeeded despite the injection of more cooling water. [...]
TEPCO says the rise in temperatures indicate . . . → Read More: Tepco: Water injections may no longer be able to properly cool down melted nuclear fuel in Reactor No. 2 — Says criticality is not taking place (VIDEO)
Critical mass, Nature Magazine, Dec. 15, 2011:
More than nine months after the nuclear-reactor disaster at Fukushima, fundamental questions about what happened remain unanswered. Without answers to these questions, Japan, and the rest of the world, is in the dark on what went wrong, what must be done now, and how to avoid similar . . . → Read More: Yomiuri: Former Japan PM ‘hints’ of recriticality at Fukushima — Found Chlorine-38 in Reactor No. 1 water tested at research institute
Japan Set to Declare Control Over Damaged Nuclear Reactors, New York Times by Martin Fackler, Dec 14, 2011:
[...] Murray E. Jennex, an expert on nuclear containment at San Diego State University [...] said he believed the government’s claim that the reactors themselves were now stable, and particularly that the resumption of the heat-producing . . . → Read More: NYT on Recriticality: Japan nuclear prof. says chain reaction at Fukushima can’t be ruled out — Disagrees with expert in America who says it’s unlikely
Breaking news ; Possibility of recriticality again, Fukushima Diary, Dec. 11, 2011:
Radioactive Iodine was measured in Gunma and Tokyo again Officials announce the reason is unknown Measured from incineration ash of garbage disposal facilities in Tokyo
Results I-131 @ 350 Bq/kg, Kita garbage disposal facility (Nov. 9) I-131 @ 28 Bq/kg, Suginami . . . → Read More: Iodine-131 detected in Tokyo at multiple locations during November — 350 bq/kg at Kita garbage facility
Breaking news ; Possibility of recriticality again, Fukushima Diary, Dec. 11, 2011:
In Gunma Samples were taken from Nov. 21 – Dec. 1 4-10 Bq/kg of radioactive Iodine were measured at 3 sewage-treatment plants [Tamamura cho, Kiryu, and Hiratsuka] 29-68 Bq/kg of Cesium were also measured at 5 sewage-treatment plants in Gunma
Google Translation: . . . → Read More: Radioactive iodine found in Gunma at 3 sewage plants — “Possibility of recriticality again”
Ian Fairlie Bio, The Guardian: Dr Ian Fairlie is an independent consultant on radiation risks and a former scientific secretary to the [UK] government’s Committee Examining Radiation Risks from Internal Emitters.
Title: Ian Fairlie on the significance of the Fukushima disaster
Program: If You Love This Planet
Date Aired: Oct. 21, 2011
Description: Dr. . . . → Read More: Radiation expert: “I’m not ruling out a nuclear bomb-type explosion” at Fukushima (VIDEO)
Nov. 6 — Radiation expert Christopher Busby’s paper, The significance of Xenon isotope ratios in the Fukushima catastrophe, was posted by Mochizuki on Nov. 5.
He says the activity ratio for xenon isotopes reported by TEPCO can only result from:
1) “An enriched Uranium fission having occurred about 50 hours before the samples were . . . → Read More: Busby: On-going fission is occurring at Fukushima — Either a recent “enriched uranium fission” or an “explosive criticality”
Nov. 3 — “A rare type of radioactive decay, not a renewed chain reaction, appears to have produced the radioactive xenon gas,” reports CNN.
According to the report, on Thursday Tepco said “it believed the gases were produced by ‘spontaneous fission’ of uranium, since the shorter-lived isotope persisted after the use of boric acid”.
. . . → Read More: CNN: Tepco’s claim of ‘spontaneous’ fission is an “improbable phenomenon” says nuke professor — Strange that such a “rare” event was detected almost immediately after sampling began?
Nov. 3, 8:30 pm ET (Emphasis Added) — A report published at 8:30 pm ET by the Japan Times calls on Tepco and the Japan gov’t to “find out true reactor conditions” at Fukushima.
Tepco announced Wednesday that, according to the Times, “There is the possibility that criticality, a sustained nuclear chain reaction, had . . . → Read More: Japan Times: It is now a “grave situation” at Fukushima — “Plutonium fission” mentioned for first time — “Criticality is very likely to have occurred”
Fukushima xenon from spontaneous decay, World Nuclear News*, November 3, 2011 at 10:30 am ET:
Excerpt“Tepco said it considered the source of the xenon to be spontaneous fission on those grounds that it had injected boric acid to the reactor vessel to reduce the likelihood of chain fission reactions but was still able to . . . → Read More: Boric acid apparently not working to stop chain fission reactions because Xenon is still being detected — Tepco says this is reason why they claim ‘spontaneous’ fission, not sustained criticality
Tepco: Xenon At Fukushima Not Result Of “Critical” Nuclear Reaction, Wall Street Journal, November 2, 2011 at 11:13 pm ET:
“Tokyo Electric Power Co. (9501.TO) said Thursday the detection of radioactive xenon at its stricken Fukushima Daiichi power plant, indicating recent nuclear fission, was not the result of a sustained nuclear chain reaction known . . . → Read More: Tepco blames ‘spontaneous’ and ‘natural’ nuclear fission for radioactive xenon… What about the 14,000% increase in Krypton-85?
Nov. 2 — Unexpected bursts of fission “threaten to increase the amount of dangerous radioactive elements leaking from the complex and complicate cleanup efforts, raising startling questions about how much remains uncertain at the plant” in Fukushima, reports the New York Times.
“The three reactors — together with spent fuel rods stored at a . . . → Read More: New fission raises “startling questions” says NYT — Koide: Harmful radioactive material in danger of leaking after a re-criticality